code: def test_drop_duplicates(self, data, categories, expected):
      idx = CategoricalIndex(data, categories=categories, name="foo")
      for keep, e in expected.items():
          tm.assert_numpy_array_equal(idx.duplicated(keep=keep), e)
          e = idx[~e]
          result = idx.drop_duplicates(keep=keep)
          tm.assert_index_equal(result, e)
  
imports: import numpy
  import pytest
  from pandas._config import using_pyarrow_string_dtype
  from pandas._libs import index
  from pandas._libs.arrays import NDArrayBacked
  import pandas
  from pandas import Categorical, CategoricalDtype
  import pandas._testing
  from pandas.core.indexes.api import CategoricalIndex, Index
label_desc: Use image node_id 8 for calling the TestCategoricalIndex obj's underlying member method code with example usage: obj.test_drop_duplicates(data, categories, expected) without return types